How does an autotransformer work? Is there a big guy to explain?

How it works:

1. Autotransformer.

The output and input share a set of coils, and the boost and buck are realized by different taps, and the part of the tap that is less than the common coil is used as a secondary, and the output voltage decreases, and vice versa, the output voltage increases.

2. When the input part of the autotransformer is connected to the coil, AC power is passed.

(i.e., the primary coil), an alternating magnetic field is generated in the core, and the alternating magnetic field induces an electromotive force in the secondary coil.

The primary and secondary coils belong to the same coil (autocoupling). Take a look at Minrong Electric Group, there are a lot of real, practical explanations**, Minrong transformer is quite good, if there are electrical problems, you can check Minrong Electric Group.

3. There is only one winding of the autotransformer, usually the part of the winding that belongs to the primary and secondary at the same time is called the common winding, and the rest of the autotransformer is called the series winding, compared with the ordinary transformer, the autotransformer with the same capacity is not only small in size, but also has high efficiency, and the larger the transformer capacity, the higher the voltage This advantage is more prominent. Check out Minrong Electric Group, there are a lot of transformer explanations, about the principle of transformer.

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4. The autotransformer is a kind of coil transformer, and the primary and secondary use a winding together, and a neutral line can be used together, which can easily realize the voltage adjustment.

5. Because the primary and secondary coils of the autotransformer are directly connected and there is no isolation, there is a risk of leakage.

An autotransformer refers to a transformer whose windings are primary and secondary on the same winding, and the primary and secondary windings are directly connected in series and self-coupled. According to the structure, it can also be subdivided into adjustable pressure type and fixed type. The coupling of autocoupling is the meaning of electromagnetic coupling, the ordinary transformer is through the electromagnetic coupling of the primary and secondary coils to transmit energy, the primary and secondary sides have no direct electrical connection, the primary and secondary sides of the autotransformer have direct electrical connection, and its low-voltage coil is part of the high-voltage coil.

Protective equipment such as autotransformers are also used in the protective equipment of communication lines.

Brief introduction. The secondary winding of an autotransformer is an integral part of the primary winding, and such a transformer appears to have only one winding, so it is also called a "single-winding transformer". The primary and secondary side coupled inductors can be decoupled according to the three-terminal coupled inductors connected to the different ends in circuit theory.

The equivalent leakage reactance attributed to the primary or secondary side of the autotransformer can be obtained by applying a voltage on the primary side and shorting the secondary side, or by applying a voltage to the secondary side and shorting the primary side[1]. An autotransformer is a special transformer that does not need insulation for primary and secondary stages, that is, a special transformer that shares a set of coils for the output and input. In other words, the primary and secondary transformers are on the same winding resistor.

Wiring diagram of the principle of autotransformer.

Peculiarity. Since the calculated capacity of the autotransformer is less than the rated capacity. Therefore, at the same rated capacity, the main size of the autotransformer is smaller, and the effective material (silicon steel sheet and wire) and structural material (steel) are reduced accordingly, thus reducing the cost.

The reduction of effective materials leads to a corresponding reduction in copper and iron consumption, so the efficiency of the autotransformer is higher. At the same time, due to the reduction of the main size and mass, it is possible to manufacture a single transformer with a larger capacity under the allowable transportation conditions. However, these advantages are usually only apparent when there is only k 2 in autotransformers.

Because the short-circuit impedance standard value of the autotransformer is smaller than that of the double-winding transformer, the voltage change rate is smaller, but the short-circuit current is larger.

Due to the autotransformer.

There is a direct connection between the primary and secondary electricity, and when the high-voltage side is over-voltaged, it will cause serious overvoltage on the low-voltage side. In order to avoid this danger, it is necessary to install a lightning arrester once or twice, do not think.

The primary and secondary windings are connected in series, and can be omitted once and twice.

In general transformers. The on-load voltage regulating device is often connected to the neutral point of the ground, so that the voltage level of the voltage regulating device can be lower than that of the first end of the voltage regulation. The neutral voltage regulation side of the autotransformer will bring about the so-called related voltage regulation problem.

Therefore, when the autotransformer is required to regulate the voltage on load, the line-end voltage regulation mode can only be used.

An autotransformer is one in which part of its winding is shared between the high voltage side and the low voltage side. The other part belongs only to the high-pressure edge. According to the structure, it can also be subdivided into adjustable pressure type and fixed type.

The coupling of autocoupling is the meaning of electromagnetic coupling, the ordinary transformer is through the electromagnetic coupling of the primary and secondary coils to transmit energy, the primary and secondary sides have no direct electrical connection, the primary and secondary sides of the autotransformer have a direct point connection, and its low-voltage coil is part of the high-voltage coil. In the current power grid, autotransformers only begin to have autotransformers from the 220kV voltage level, which are mostly used as contact transformers between power grids. Below 220kV, there is almost no autocoupling.

For dry-type transformers, its insulating medium is a solid such as resin, and there is no insulating oil in oil-immersed transformers, so it is called dry-type. Due to the poor heat dissipation conditions, the capacity of dry-type transformers can not be very large, generally only small and medium-sized transformers, and the voltage level is also 35kv and below, and there is almost no higher than 35kv. The working principle of an autotransformer 1. An autotransformer is a special transformer that shares a set of coils for the output and input.

Boosting and stepping down is achieved with different taps. The voltage of the tap is reduced if there is less than the common coil. The voltage of the partial tap that is more than the common coil increases.

2 In fact, the principle is the same as that of an ordinary transformer, except that his original coil is its secondary coil The general transformer is a primary coil on the left through electromagnetic induction, so that the secondary coil on the right generates voltage, and the autotransformer affects itself 3 The autotransformer is a transformer with only one winding, and when used as a step-down transformer, a part of the wire turns are extracted from the winding as a secondary winding; When used as a step-up transformer, the applied voltage is only applied to the turn-part of the winding. Usually the part of the winding that belongs to both the primary and secondary is called the common winding, and the rest is called the series winding, compared with the ordinary transformer, the self-coupling transformer with the same capacity is not only small in size, but also has high efficiency, and the larger the transformer capacity, the higher the voltage. This advantage is even more prominent.

Therefore, with the development of the power system, the improvement of the voltage level and the increase of the transmission capacity, the self-lotus transformer has been widely used due to its large capacity, low loss and low cost. on.

Principle: After the motor is started, the motor is separated from the autotransformer, so as to move normally under full voltage. This step-down start is divided into two types: manual control and automatic control.

The high-voltage side of the autotransformer is fed into the grid, and the low-voltage side is connected to the motor, and there are several taps with different voltage ratios to choose from.

The working principle of the autotransformer is that when a coil is connected to the AC power supply (that is, the primary coil), an alternating current flows through the coil, and this alternating current generates an alternating magnetic field in the core, and the alternating main magnetic flux generates its own induced electromotive force in the primary coil, and at the same time, the other coil (that is, the secondary coil) induces mutual inductive electromotive force. By changing the relationship between the ratio of the turns of the primary and secondary coils, the voltage at the end of the primary and secondary coils is changed to realize the voltage conversion.

When an autotransformer is used as a step-down transformer, a part of the line turns are extracted from the winding as a secondary winding; When used as a step-up transformer, the applied voltage is only applied to the turn-part of the winding. Usually the part of the winding that belongs to both the primary and secondary is called the common winding, and the rest of the autotransformer is called the series winding, and the autotransformer with the same capacity is not only small in size compared with the ordinary transformer, but also has high efficiency, and the larger the transformer capacity, the higher the voltage.

This advantage is even more prominent. Therefore, with the development of power system, the improvement of voltage level and the increase of transmission capacity, autotransformers have been widely used due to their large capacity, small loss and low cost.

Electrician knowledge: autotransformer step-down starting circuit, working principle, wiring steps explained one by one.

Ordinary transformers include primary coils and secondary coils. The self-even transformer is not divided into primary secondary coils, and the outermost layer of the self-even transformer coil, that is, the outermost edge of the coil, that is, a wire head of the coil is wound, which is equivalent to the connection of the primary secondary coil. The innermost part of the transformer (where the coil begins to wrap) is a wire end.

On the outer enamelled wire coil, connect one or more heads, and there will be a small voltage output.

Whether it is an ordinary transformer or an autotransformer, it uses the principle of electromagnetic induction.

No matter what form of transformer, it uses the principle of electromagnetic induction to work.

Dear users, Hello autotransformer is a type of transformer that has only one coil instead of two coils. A part of the coil is used as both an input and an output. Autotransformers work by using electromagnetic induction to transfer electrical energy from one circuit to another.

The advantages of autotransformers are small size, light weight, low cost, and high efficiency, so they are widely used in electronic equipment, communication equipment, medical equipment and other fields. The working principle of the autotransformer is to use electromagnetic induction, when the current at the input end changes, a magnetic field will be generated in the first circle, and this magnetic field will pass through the other part of the coil, thus generating a potential difference at the output end. The output voltage of the autotransformer can be adjusted by changing the voltage at the input.

The difference between an autotransformer and a normal transformer is that an autotransformer has only one coil, so there is no electrical isolation between the input and output. This means that if the voltage difference between the input and output is too large, it can lead to a short circuit or a risk of electric shock. Therefore, special attention needs to be paid to safety when using autotransformers.

Off-topic: Another application of autotransformers is in audio Wuxiao amplifiers, which are used to increase power. In audio amplifiers, an autotransformer is used as a coupler to transmit the output signal from the preamplifier to the postamplifier, thereby increasing the power of the entire spine grinding amplifier.